Conventionally, as a technique of executing close proximity wireless transfer between communication devices using an electromagnetic coupling, for example, an RFID technique and an NFC technique are well known, and are used as an information transmission means. These techniques are defined by the JIS standard “X6319-4: 2005”, the ISO standard “ISO 18092:2004”, and the like. Note that RFID is an abbreviation for Radio Frequency IDentification and NFC is an abbreviation for Near Field Communication.
On the other hand, there is known a non-contact power transmission means for transmitting a power between opposing devices using an electromagnetically induced electromotive force to charge secondary batteries arranged within the devices.
A communication device which includes the above-described information transmission means and non-contact power transmission means, and is capable of transmitting information and a power in a non-contact manner is expected to be available.
In the case of such communication device, if the information transmission means and the power transmission means are configured to independently operate, electromagnetic induction in the non-contact power transmission means generates noise in wireless communication using the information transmission means, thereby degrading the communication quality.
Therefore, Japanese Patent Laid-Open No. 2001-102974 has proposed to configure the information transmission means and power transmission means to cooperatively operate, and then execute exclusive control. According to this patent reference, when starting an information transmission operation or power transmission operation on the basis of a user instruction, if either of the means is operating, the other means is controlled to deny or suspend the start of the operation.
In the case of the above-described exclusive control, however, even though the remaining level of the secondary battery of the communication device falls into a critical state during information transmission by the information transmission means, charging is not immediately started. Therefore, the secondary battery may be exhausted during the information transmission, thereby causing the communication device to operate unstably.